Question: Simplify the expression. $ (5r^{4}-2r^{3}) - ( 6r^{7}+6r^{4}) - ( -2r^{6}-4r^{4}) $
Answer: Distribute any negative signs. $(5r^{4}-2r^{3}) + (-6r^{7}-6r^{4}) + (2r^{6}+4r^{4})$ Since we are adding polynomials, we can simply remove the parentheses. $5r^{4}-2r^{3} - 6r^{7}-6r^{4} + 2r^{6}+4r^{4}$ Identify like terms. $ + {5 r^4} - \color{#9D38BD}{2 r^3} - {6 r^7} - {6 r^4} + \color{#DF0030}{2 r^6} + {4 r^4} $ Combine like terms. $ { -6 r^7} + \color{#DF0030}{ 2 r^6} + { r^4} + \color{#9D38BD}{ -2 r^3} $ Add the coefficients. $-6r^{7}+2r^{6}+3r^{4}-2r^{3}$